This invention relates to medical devices and methods. More particularly, the invention relates to prostheses that can be used for such purposes as remodeling soft body tissue structures of a patient, and to instruments and methods that can be used for implanting such prostheses in a patient.
An example of a context in which this invention can be used is in a medical procedure that may be referred to as percutaneous mitral valve repair. Hindrichs et al. U.S. patent application Ser. No. 10/803,287, filed Mar. 17, 2004 (and hereby incorporated by reference herein in its entirety), shows this type of procedure, and methods and apparatus for performing it. An embodiment of this type of procedure includes percutaneously implanting a first anchor structure in the coronary sinus of the patient (e.g., through the wall of the coronary sinus and into the myocardium below). Then a second anchor structure is percutaneously implanted in the right atrium of the patient outside the ostium of the coronary sinus. Lastly, the distance between the two anchor structures is reduced by percutaneously tightening a linkage (e.g., of suture material) between those structures. Because the coronary sinus is on the heart close to a portion of the annulus of the mitral valve, shortening the distance between the above-mentioned anchor structures shortens the mitral valve annulus. This is beneficial to a patient whose mitral valve annulus is enlarged and whose mitral valve is therefore no longer able to close properly.
Improvements to procedures, prostheses, and related instrumentation of the type illustrated by the foregoing are always sought. For example, it is important to have anchor structures that will not come out of the tissue in which they are implanted.
The percutaneous mitral valve repair procedure mentioned in the preceding paragraphs is only one example of soft body tissue remodeling to which this type of technology may be applied. Other examples include (without limitation) (1) remodeling of a patient's left ventricle, (2) intra-atrial remodeling of a patient's mitral valve annulus, (3) intra-ventricular remodeling of a patient's mitral valve annulus, (4) remodeling of features of a patient's tricuspid valve, and (5) other cardiac applications. What is needed in many soft body tissue remodeling applications is long-term (chronic) durability of the prosthesis under dynamic loading of the prosthesis.